1.\" $OpenBSD: vget.9,v 1.11 2013/06/04 19:27:16 schwarze Exp $ 2.\" 3.\" Copyright (c) 1996 Doug Rabson 4.\" 5.\" All rights reserved. 6.\" 7.\" This program is free software. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR 19.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT, 22.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28.\" 29.\" $FreeBSD: src/share/man/man9/vget.9,v 1.7 2001/12/26 23:14:04 davidc Exp $ 30.\" 31.Dd $Mdocdate: June 4 2013 $ 32.Dt VGET 9 33.Os 34.Sh NAME 35.Nm vget 36.Nd get a vnode from the free list 37.Sh SYNOPSIS 38.In sys/param.h 39.In sys/vnode.h 40.Ft int 41.Fn vget "struct vnode *vp" "int flags" "struct proc *p" 42.Sh DESCRIPTION 43Get a vnode from the free list and increment its reference count. 44.Pp 45Its arguments are: 46.Bl -tag -width flags 47.It Fa vp 48The vnode to remove from the free list. 49.It Fa flags 50If non-zero, the vnode will also be locked. 51.It Fa p 52The process responsible for this call. 53.El 54.Pp 55When not in use, vnodes are kept on a free list. 56The vnodes still 57reference valid files but may be reused to refer to a new file at any 58time. 59Often, these vnodes are also held in caches in the system, such 60as the name cache. 61.Pp 62When a vnode which is on the free list is used again, for instance if 63the vnode was found in the name cache as a result of a call to 64.Xr VOP_LOOKUP 9 , 65then the new user must call 66.Fn vget 67to increment the reference count and remove it from the free list. 68.Sh ERRORS 69.Bl -tag -width Er 70.It Bq Er ENOENT 71The vnode 72.Fa vp 73is in the process of being cleaned out from the underlying 74file system. 75.It Bq Er EBUSY 76The vnode 77.Fa vp 78is in the process of being cleaned out from the underlying file system, and 79it wasn't possible to sleep on it because the 80.Dv LK_NOWAIT 81flag was specified. 82.El 83.Sh SEE ALSO 84.Xr vnode 9 , 85.Xr vput 9 , 86.Xr vref 9 , 87.Xr vrele 9 88.Sh AUTHORS 89This man page was originally written by 90.An Doug Rabson 91for 92.Fx . 93